


Just This Once

by Anonymous



Category: Chainsaw Man (Manga)
Genre: Ambiguous/Open Ending, Beam Being Best Boy, CSM Spoilers for Chapter 5/6, Denji Being as Straight as a Ruler, Drowning, Fluff and Humor, Hanahaki Disease, I Wrote More Of This Because I can, Kissing, M/M, Makima Is Here In Spirit, Pining, Seriously skip 6 if you're not all caught up yet, Swimming, Swimming Pools, Teaching, Unrequited Love, Vomiting, valentines day
Language: English
Status: Completed
Published: 2019-12-19
Updated: 2020-05-31
Packaged: 2021-02-26 01:47:32
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 6
Words: 1,855
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21865459
Author URL: https://archiveofourown.org/
Summary: Beam teaches Denji how to swim. Among other, fluffy things.
Relationships: Denji/Beam
Comments: 27
Kudos: 85
Collections: Anonymous





	1. Chapter 1

“Master Chainsaw! You’re doing great!” As Beam yelled with enough enthusiasm to crack the windows, it was no wonder that anyone with half a brain had long vacated the premises.

_Yeah, let’s get the shark devil to teach me how to swim! What’s the worst that could happen?_

With his arms thrashing around in all directions, water going directly up his nose and just barely managing to keep his head above the water being a huge feat in and of itself, Denji soon found himself sorely regretting those words. Beam was watching over him with avid interest, all while swimming circles around him.

Even in the midst of drowning, Denji could only think that Beam really was at his happiest when in water.

\- -

“Sorry!” Denji winced as Beam yelled again, this time, directly into his ear. It was an effort just to crane his neck up from the sopping wet floor, but Denji managed. When the devil finally came back into view, he noticed that Beam was soaking wet, himself. Had he gone to the trouble of pulling him out?

“S’Fine…” Denji was more distracted by the droplets of water trickling down his body when he found himself being tackled by the over-sized shark, his cold, muscular body clinging to his own. Beam was way too over-excited, mumbling something about his gratitude and finding a way to repay him.

Ahh.

Denji didn’t have it in him to care anymore. He wasn’t into dudes, so letting Beam cling to him like this didn’t mean anything.

Just this once, he thought.

He’d allow it.


	2. Chapter 2

**Summary for the Chapter:**

> Beam and Denji share a 'moment'.

“Master Chainsaw! I love you!!”

And just like that, the weight of a small building came crashing into Denji.

“Uwaah—Beam, get off of me! Crushing- -You’re seriously crushing me!”

The dumb, over-excitable Shark Devil sprang back at that, and at long last, Denji’s lungs no longer felt like they were being slowly squeezed to death.

“What do I keep telling you?!”

Beam winced as Denji yelled in his ear. “I don’t know my own strength…”

“E-x-a-c-t-ly! Now go sit in the corner or something, you’re just gonna get in the way when Makima-san gets here.” Honestly. So annoying. Why’d Beam have to choose now of all times to look like a kicked puppy? Oh well. He didn’t matter. Not when _Valentines Day_ was finally here.

“Ahh! I can’t wait to taste Makima-san’s chocolates!”

Finally, after 16 years of painful living, a girl was finally going to give him chocolates. More importantly, that girl was Makima. Denji could hardly wait, even though he’d been forced to all month.

Beam, for his part, remained uncharacteristically quiet as he sulked, obediently sitting in the corner. “Aww, come on. Don’t be jealous just ‘cause you’re not getting any! Makima promised she’d make some just for me!”

Okay, so maybe he should have felt a little bad about gloating, but he didn’t.

“Master Chainsaw…” Beam started, but soon closed his mouth, before quickly opening it again. “Miss Makima’s the one who sent me here. She told me to tell you, uhh, something like…I’m sorry, but I can’t make it today…?”

And just like that, the world around the Chainsaw Devil came crashing down.

“So! I thought I’d cheer you up!” Ahh. Even if Beam came crashing into him again, or confessed his love, or whatever. Denji just didn’t have it in him to care anymore.

Nothing mattered now.

“See? I brought my own chocolate!” While Beam excitedly waved some misshapen box of chocolates around, the last of Denji’s soul flew somewhere far, far away. He wanted to yell “I don’t want it from you—!!” or something equally spiteful, but the words just wouldn’t make it out of his mouth.

“Feed it to me,” were the words that came instead.

And of course, Beam complied. Just like any good friend would.


	3. Chapter 3

“Oh, Beam—That is fucking _nasty_ ,” Denji complained through a mouthful of toast, always happy to use up Aki’s food and force his breakfast down, even with the very unwanted soundtrack of a certain shark devil throwing up in the background. “Especially while I’m eating!”

“I can’t help it! Miss Makima says I have a very rare disease!” Beam cried from the bathroom, but by this point Denji was only half-listening. “You wanna know what’s really nasty? Whoever was in here last didn’t even flush!!”

Okay, so _that_ got Denji’s attention. “God, I hate Power. She’s so annoying!”

“Yeah!!” Beam hastily agreed, wiping at his mouth before sitting down and joining the chainsaw devil at the table. “Any enemy of Master Chainsaw is an enemy of mine!”

Denji just shrugged, though his mouth did twist into a little grin. “So. Does it smell like flowers in there now?”

He barked out a laugh as Beam nodded his half-shark, half-human head. “I guess we don’t need air freshener anymore, so long as we’ve got you around.”

“Oh! Miss Makima said I might die, actually.” He’d said it so casually, Denji couldn’t help spitting the rest of his drink out. Man, Aki was gonna be _pissed_.

“Why?”

That was it. That was all he could think to say. He’d never been much of a great thinker. Had never been much one for thinking, anyway. That was one sentiment him and Beam seemed to share. It was highly overrated, anyway.

“She said—I’m in _love_ with someone. I’ll die if they don’t feel the same way. Ah! You got any idea who it might be, Master Chainsaw?!” Beam jumped up, slamming his hands down on the table, nearly smashing it in two. It was insane to think someone as strong as Beam could die from something like heart-break. Then again, seeing as nothing in Denji’s life had made a lick of sense these past few months, he supposed it made a lot of sense, after all.

“Ma~an, I got _no_ idea who that is, but boy, do I feel sorry for ‘em,” Denji lied, trying to ignore that sickly feeling in his stomach, the one he got when he hadn’t eaten all day, when he couldn’t even afford to feed Pochita. “Hey, Beam. Can ya’ do me a favour?”

“Anything!” He beamed, wearing that same old, shark-y smile, and the sickness grew. It was spreading to his chest, reaching his dead, cursed heart.

The heart everybody wanted, and the one Denji had no idea how to give away.

“Can ya’…close your…Aw, fuck! You don’t even _have_ eyes!” How was he going to demand he close them, now?! He wasn’t even wearing a shirt, so it’s not like he could just grab him and get it over with quickly, either. Denji swallowed.

Come on. He’d swallowed vomit before. He could do this to save Beam.

Using the table as leverage, Denji pushed himself up, and shoved himself forward. As his forehead smacked right into Beam’s, it suddenly occurred to him that maybe this wasn’t such a good idea. Oh well. He’d never been much of a thinker, anyway.

“Master Chainsa—” He couldn’t talk, now, or maybe it was more accurate to say Denji wouldn’t let him. Whatever. It didn’t matter. It was just a kiss. He’d done more—with worse, much worse—guys than Beam before. This wasn’t such a big deal. He’d get over it. Him and his stupid flower disease. He _tasted_ like flowers, too. It was a strange thing, to have both the scent of vomit and taste of flower petals on your tongue. To be making out with a fiend, a friend and a co-worker in a house that wasn’t even his. But really, when had life ever gone his way?

“A-hem. If you’re going to do things like that _here_ , get a room next time, would you?”

Right now, Aki’s irritated voice might as well have been a million miles away.

Yeah, Denji smiled.

Right from the start,

Life had never, ever gone his way.


	4. Chapter 4

“Master Chainsaw! Can you do that thing with our mouths aga—?!” Beam jumped back in surprise as a pair of sweaty hands suddenly clamped over his mouth, smothering him into silence. If it had been anyone else, he’d have bit back, but Beam knew how to recognize Master Chainsaw by now. He had a very distinctive scent.

“I swear to God, Beam, if you don’t shut up, I’ll gut you like a fish myself!” Beam watched Denji straighten himself up, fixing his hair and everything. He always got so excited whenever they had to report to Miss Makima.

It made him happy and a little bit sad, all at the same time. Beam didn’t get why.

He stood back and watched Makima praise Denji for a job well done—if he cut in now, Master Chainsaw was sure to get mad at him again. Beam didn’t want that.

Seeing him smile was nice, but seeing him blush always hurt. Beam didn’t get that, either.

Only one thing was sure. The disease known as ‘Love’ was terribly confusing.


	5. The Devil of the Dark

**Summary for the Chapter:**

> Hey, so this chapter isn't like the previous chapters. It's more of a re-write of chapter 65 of the manga. So, a spoiler warning!

Denji awoke to the taste of blood.

That sickly iron spreading down his throat, awakening his transformation.

He didn’t want this. He’d take the taste of vomit over this. Anything, but this.

**< But life never goes your way, does it, Denji?>**

_No, disembodied voice in my head. No, it does not._

He wishes they weren’t in Hell.

He wishes there wasn’t half a chainsaw sticking out of his skull.

He really, really wishes Beam wasn’t spoon-feeding his own blood into his open mouth right now. While he’s at it, he can also go ahead and wish that Beam wasn’t missing around a quarter of his limbs, give or take. Was never the best at math, never having gone to school and all.

“Master Chainsaw…”

Oh. That was new.

Beam had never sounded so desperate before.

“Please, revive…” Don’t. Don’t say that. “And grant…Our Prayers…”

_Do it your damn self—!! Don’t talk like you’re going away somewhere!_

That’s what Denji wants to scream, but he can’t say anything. His mouth is agape, all bloodied and yet so empty. And then in the blink of an eye; The rest of Beam’s body joins the rank of Denji’s arm, and what’s left of his sanity:

Lying bloodied on the floor, detached from himself, slain into several pieces.

Ahh.

Beam was going to die, wasn’t he?

Even as the darkness closed in and the end draws near,

Denji could only think—

**“This fucking sucks.”**


	6. Rain

**Summary for the Chapter:**

> Hey, so this chapter isn't like the previous chapters. It's more of a re-write of chapter 71 of the manga. So, big spoiler warning!

“Beam’s dead.”

Aki says, yet the words don’t sink in.

_Beam’s dead._

Denji eats, but the food has no flavour.

_Beam’s dead._

Makima invites, yet Denji declines.

_Beam’s dead._

Power clings, but he can’t feel anything.

It’s only when Denji walks alone at night, looks up at the empty sky and feels the soft, pitter-patter of raindrops on his shoulders that _something_ starts to sink in.

“Beam’s dead,” and he smiles, because he knows Beam would want him to.

He thinks about all the puddles Beam used to jump in. He considers that he’ll never have anyone else call him “Master Chainsaw!” again.

Denji decides to take the long way home, smiling as the rain soaks into his skin.


End file.
